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(No Model.) Y 3 sheets-sheen 1.

G. H. FITCH.

PRESURPTION WEIGHING SCALE.

No. 384,247. Patented June 12, 1888.

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WIQJVESSES (No Model.) A 3 Sheets-Sheet. 2, C. H, FITCH.

PRESGRIPTION WEIGHING SCALE. ',No. 384,247. Patented June 12, 1888.

@Zwd/M Mw WAM (No Model.) 3 Sheets-Sheet 3.

C. H. FITCH.

PRESCRIPTION WEIGHING SCALE.

No. 384,247. Patented June 12, 1888.

WITNESSES,

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UNITED STATES PATENT OEEICE,

CALVlN H'. FITCH, OF POULTNEY, VERMONT,

PRESCRIPTION-WElGHING SCALE.

SPECIFICATION 'ieri-ning part of Letters Patent No. 384,2t7, dated June 113.888,

application tiled July 15, ISST To @ZZ whom it 11mg/ concern:

Be it known that I, @drivin H Frreii, a citizen ofthe United States, residing at Poultney, inthe county of Rutland and State of Verinont, have invented certain new and useful Improvements in Prescription-Scales,of which the following is a full, clear, and exact de scription.

The object of this invention isto provide an accurate, compact, and attractive prescrip tioinscale for druggists, in which sinall quanA titles may be accurately weighed without the use of detached weights.

Another object is te so construct the scale, as upon the linockdown77 principle, that it may be disassembled and its parts packed in small compass for trans portation,and the scales thereafter accurately set up or assembled for use; and still another object is to provide means for leveling the scales.

lVith these objects in view the invention consists in the details of construction and in certain combinations, as hereinafter more particularly set forth and claimed.

In the accompanying drawings, in the several igures of which like parts are similarly designated, Figure l is a side elevation; Fig. 2, a vertical section with the beam in elevationd Fig. 3 is a section in the plane of line g/yofFigzl. FigAisaverticalsectionthrough one of the posts. Fig. 5 is a perspective view of the spirit-level, and Fig. ll shows in section an elevation of details of the beanrloclriug device.

The foundation er base plate o may be a piece of brass or other nietal shaped in dies or otherwise, and provided at its four corners with bosses b and screws c, which bosses and screws receive legs or feet d, having milled collars, whereby the said legs may be adjusted toward and from the said base-plate to level the said base-plate with respect to the surface upon which it is placed, the bosses Z1 litting within recesses in the upper ends of the legs, so that the legs may have a positive bearing upon the said bosses at all ordinary adjustments thereof with relation to the base-plate, and thereby insure a steadiness of the legs. Four posts, e, are supported upon the four corners of the upper surface of the base-plate a, and these posts receive and support the up- (No model.)

per bearing-plate, f, which latter may also be formed in substantiallyv the saine manner and ofthe saine material as the base-plate 'ieferring to Fig, et, these several posts e have at their lower ends a screw, c', projecting through the base-plate and engaged ou the under side of the said base-plate by a nut, et, and at their upper ends are provided with screw-threaded sockets el, which engage screws ci, the heads whereof rest upon the upper bearingplate, j', and are prevented from rotating by pins c5en gaging holes in the upper surface ol" said bearing-plate. Theposts are provided with inilled collars eJ'. The screws eand the screw-sockets c2 may be rights and leds, so that when the posts are rotated they will disengage theinselves from both the nuts el and the screws e* to permit the separation of the plates o and j'.

The plate fis provided with a pocket, j", in which is arranged a circular rotatingspiritlevelLo. Theconstructionofthislcvelisshown in detail in Figs. 2 and 5.

g is ablocl; of inetalorother inaterialscrew threaded externally and provided iuteriorly, and substantially in the line of its diameter, with an ordinary level orbubble tube, gt'. This block g receives a screw-threaded cap, g, in which is a leveling sight, gt. The block g' is provided with a screw, g5, which projects through the pocketf, and is engaged by a nut, g, whereby the said level inay be rotated within its pocket to ascertain both the transverse and longitudinal horizontulity ol` the scales. The upper edge, gf, ol' the cap g3 may be niilled to provide a hand-grasp for rotating the level. The rotation of the level maybe limited to bringing the bubbletube into two positions, which are at right angles to each the block g may be provided with a groove, g5, into which a stop-pin, j, in the pocketf may be projected.

it will be observed that scales provided with these leveling-feet and with the spirit-level may be always set perfectly true, no matter how irregular the counter may be upon which they are placed. And this is a very iniportant feature,in that by it the beam. will always be preserved in a true position, and there will be no binding of its knife-edges in their bear ings, nor will there be any friction of the beam other, and for this purpose the under side of l IOO itself against any portion of the frame in which it is hung. The beam h in the instance herein shown consists of an upper member, h', graduated to grains and half-grains, and provided with a permanently-attached counterpoise, It, adapted to be slid along the beam, and a second member, h, graduated into drams and quarters, and having its zero-point in vertical alignment with the knife-edges of the beam. This member h3 is also provided with a sliding permanentlyattached counterpoise, h4. By arranging the zero-point of the lower member of the beam immediately under the knifeedges of the beam I'am enabled to secure absolute accuracy in weighing with a beam having two scales and supporting members, and still having these two members of the beam practically one beam.

It will be observed that the two members 7L and 7b3 of the beam are rigidly connected at both ends.

The knife-edge t of the beam is supported upon steel plates t" t in a circular yoke or bearing,j. (See Fig. 3.) This yokej is pierced diametrically with openings 7" j opposite the bearings t" i', and these openings are covered by swinging caps j2 ji. I/Vhen it is desired to place the beam in its bearings, one of the caps jZ is swung aside and the knife-edgez' is passed through the opening j sufficiently' to permit the opposite end of the knife-edge to be set in its bearing t" and extended into the openingj, and when so extended and its end comes substantially in contact with the cap ji at that end, then the cap of the opposite opening may be swung down and fastened over said opening, thus confining the knife-edge upon its bearings and within the opening, and preventing end- Wise movement of the knife-edge in its bearings, and at the same time covering up and protecting the said knife-edge.

The yoke]l may be made by slitting a tubular piece of metal in rings of the proper width, and thereafter boring the diametrical openings. In this way the bearings for the beam may be Very economically manu faetured. The yokej is supported upon the bearing-plate f by a post, k, which post has a downwardlyprojecting screw, 7c', extended through the plate fand engaged by the nut k2.

The scale-pan Z is made with a standard, Z', whereby the said pan may be fitted in its socket m; and this socket may be, and preferably is, in order to prevent lodgment of dust, an open-ended tube arranged upon the top of the yoke n, which is constructed with steel bearings a ca )s n2 and diametricall o 7 1 y opposite openings for the reception of the knife-edge n of the scale-beam,to support the scale-pan. The bearing-edges of the knifeedges t' and a are reversed, of course, and they are in the same horizontal plane when the scale is in equilibrio. The yoke a is connected by the rod o with a steadying-lever, o', pivoted to the under side of the base-plate a in any usual manner, the rod o passing through suitably-hushed openings o2 o2 in the plates f and a; and this said rod o may be provided with any suitable counterpoises, o3 o3, to balance the beam.

The free end of the beam projects into the slotted post p, secured to the forward end of the platef by a screw, p', and nut-p2, and held against rotation by a pin, p, engaging a hole or socket in the upper surface of the platef.

This post 1J in the process of its manufacture is provided with slits or kerfs p in the longitudinal side walls of its slot, in which slits or kerfs are arranged oppositely-moving beamlocking devices q, and thereafter these kerfs are practieall y covered up by inserted strips pi. These beam-locking devices are engaged by a serpentine cam, o', mounted to rotate upon the top of the post p and provided with a surrounding cover or cap and a rotating dei vice, s, thetwo being united to the post by a rivet or screw, s; and the cam 1' and cap s being united to one another so as to turn together by a pin, o", which also serves the additional purpose of a stop by playing in a semicircular groove, r2, in the top of the post p. (See Figs. 2 and G.) It will be observed that as the cam r is rotated the active ends q q of the beam-locking device will be caused to approach toward or recede from each other, and their limitof approach is arranged in line with the active edge of the knife-edge i, so as to hold the beam in a true horizontal position. The beam co-operates with these beam-locking devices by means of a screw, t, set in the free end of the beam and passing between opposite edges of the active ends q of the beamlocking devices. This screwt subserves the additional purpose of a counterpoise or equalizer for the beam, for by adjusting it back and forth in its bearing in the beam the length of the beam, and consequently its weight as a lever, are increased or diminished. The cam 1' effects the complete movement of the beamlocking devices by about a quarter or nearly half turn, and thus the beam may be very readily and very quickly rendered rigid and immovable. This is a decided advantage in this class of scales where the knife edges are necessarily iine, and the vibration of the beam, if left unrestrained,wears rapidly upon the knife-edges, and hence destroys the accuracy of the balance.

I desire to call attention .to the facilities for disassembling the scale in order to pack it for transportation. The pan Z is simply lifted from its socket, when the yoken and its counterpoises are readily detached. The yoke z', with its post or standard, is readily detached from the plate f. The beam 7L is readily lifted out of its yoke and disconnected from the posti). The

post 1J, with its appurtenances, is removable bodily from the platef by removing the nut p2, and the plates a and f are disconnected by rotation of the posts e.

Scales thus constructed may be arranged within any suitable protecting-case.

l. A prescription-scale comprising a pan IOO and a beam provided with the permanentlyixed sliding weights, a bearing-plate, a post to which the beam is pivoted and which is detachably connected to the said bearing-plate, a foundation-plate, and removable posts interposed between the foundation-plate and bearingplate to render the former detachable from the bearingplate, wherebyT the parts of the scale may be readily disassembled and the scales knocked down 7 for storage and trans portation, substantially as described.

2. A foundation-plate provided with levelingfeet, a bearingplate, and detachable posts connecting` the two plates, and a spirit-level arranged in the upper plate and rotatable therein, so as to be brought lengthwise and crosswise of the plate, to ascertain the level of said plate longitm'linally and transversely, combined with a scale-pan, a scale-beam, and bearings therefor arranged upon the bearingplate, substantially as described.

8. A scale having a rotary spirit-level eonsisting of a bleek provided with a bubble-tube, a cap connected with said block by serewthreads, and having a sight for the bubbletnbe,and the bearing-plateof the scales having a pocket in which the level is arranged, substantiall)7 as described.

4. A scale-beam having two rigidIycOnnected or integral graduated members, with the zero-point of the lower member in vertical alignment with the knifeedge ofthe beam, and provided with permanently-atlixed sliding weights, combined with such knife-edge, bearings therefor, and a scale-pan and its eonnterpoises, substantially as described.

5. The post provided with oppositelynioving beam-locking devices, a cani for moving said devices, and a cap covering the saine and adapted to rotate it, snbstantiallg7 as described.

6. A pest having longitudinal recesses or keriseonibined with opposil'cly-moving beanr locking devices, a serpentine cam engaging said beam locking devices, and means to rotate said cam to grasp and release the beam, substantially as described.

7. A, sealebeain having an eqnalizing device in the i'orin of a screw arranged at its free end, combined with apost and beainlocking devices cooperating with said eqnalizing device, and means to move said devices toward and from said eqnalizing device, snbstantially as described.

In testimony whereol' l have hereunto set my hand this 13th day of .lnly,`. D. 'i357'.

CALVIN H. FITCH.

YWitnesses:

MARTIN D. COLE, A. H. Tanner. 

